/Engine/Source/Runtime/UMG/Public/Blueprint/WidgetBlueprintLibrary.h
Find all widgets of a certain class.
static void GetAllWidgetsOfClass ( [UObject](API\Runtime\CoreUObject\UObject\UObject) * WorldContextObject, [TArray](API\Runtime\Core\Containers\TArray)< [UUserWidget](API\Runtime\UMG\Blueprint\UUserWidget) * > & FoundWidgets, [TSubclassOf](API\Runtime\CoreUObject\Templates\TSubclassOf)< [UUserWidget](API\Runtime\UMG\Blueprint\UUserWidget) > WidgetClass, bool TopLevelOnly )